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I I I I I I I I I I I I I I I I I I I dewatering, or point pollution sources and; 3) identify habitat features that required additional quantification, i.e. potential spawning area and nursery areas. Quantitative habitat analysis included: 1) counts of backwaters and potential spawning areas; 2) documenting physical attributes of potential spawning areas; 3) compiling and presenting USGS flow data for the Dolores River system. Backwater counts included all backwaters encountered while traversing any portion of the study area during a field trip. Criteria used to delineate a backwater were: 1) the length of the backwater exceeded the width at the mouth and; 2) surface area of the backwater was at least 15 m2. Density of backwaters is reported as number of backwaters per mile of river. Physical measurements of backwaters including water depth, surface area and substrate type were made for all backwaters sampled. Surface area was estimated for all backwaters counted but not sampled. A preliminary count of potential spawning areas was made within the study area during 1990. Classification of these sites as potential spawning areas was based on the presence of deep pools in proximity to and interspersed with cobble riffle habitat (Biological Subcommittee 1984). Further refinement of the number of potential spawning areas will be made based on described spawning sites in the Yampa River, a system with habitat features similar to the Dolores River. Physical characteristics of these area included: 1) suitable spawning habitat (graveVcobble/boulder bars with average depths of 1 to 3 feet and velocities of 1 to 3 fps) and; 2) suitable resting or staging habitat consisting of pools and eddies with average depth of 6 feet and velocities of. 1 f/s or less. This refinement process will involve visiting the study area during the time that temperatures and flows are appropriate for spawning of Colorado squawfish and conducting additional habitat measurements on potential sites. Three potential spawning sites were selected as representative of this habitat type in the Dolores River. Maps and detailed measurements of the physical attributes of these sites were made in 1990 under low flow conditions. Scaled maps were produced for each of these sites showing channel configuration, water depths, surface habitat features, substrates, and substrate embeddedness. Additional measurements will be taken in 1991 when temperatures and flows are appropriate for spawning by Colorado squawfish. 3.4 Water Qualitv and Macroinvertebrate Sampling Locations of water quality and invertebrate sampling sites are presented in Figure 2. Water quality analysis performed on Dolores River samples are presented in Table 3. Water samples represent grab samples taken at one point in time and integrated across the channel at the sample site. All water samples were stored in coolers at 4DC until processing. Water quality analyses were performed by ChemTech laboratories in Murray, Utah. Additional water quality parameters including conductivity and salinity were measured afield using a YSI temperature/conductivity/salinity meter. Benthic macroinvertebrates were sampled using a modified Hess sampler with a one square foot opening. An attempt was made to select sampling sites that were geomophologically similar. However natural variation in channel morphology created minor differences between sampling sites. Macroinvertebrate sampling sites were located in cobble riffles, with velocities ranging from 1.0 to 2.0 feet per second and depths of 0.8 to 1.2 feet. Substrate generally consisted of 3-10 inch rounded cobble, with the exception of the sampling site immediately above the San Miguel River, which was composed of 6-12 inch angular rock. Two to four sample replications were collected within similar habitat at each sampling site. Additional qualitative samples were collected at each sampling site in a range of habitats to confirm the variety of macroinvertebrates reported by the quantitative samples. 7